[Scummvm-git-logs] scummvm master -> 9a9a13605f543f2bc59fdd6d236986a6d10258d5

[sluicebox]

This automated email contains information about 1 new commit which have been
pushed to the 'scummvm' repo located at https://github.com/scummvm/scummvm .

Summary:
9a9a13605f SCI: Fix SQ1VGA buckazoid inventory crash


Commit: 9a9a13605f543f2bc59fdd6d236986a6d10258d5
    https://github.com/scummvm/scummvm/commit/9a9a13605f543f2bc59fdd6d236986a6d10258d5
Author: sluicebox (22204938+sluicebox at users.noreply.github.com)
Date: 2023-12-14T16:26:00-08:00

Commit Message:
SCI: Fix SQ1VGA buckazoid inventory crash

Big thank you to @codengine for discovering this script bug, performing
the script analysis, and developing the initial script patch.

Changed paths:
    engines/sci/engine/script_patches.cpp


diff --git a/engines/sci/engine/script_patches.cpp b/engines/sci/engine/script_patches.cpp
index 40ca807edad..f4fa67c90f1 100644
--- a/engines/sci/engine/script_patches.cpp
+++ b/engines/sci/engine/script_patches.cpp
@@ -23527,8 +23527,46 @@ static const uint16 sq1vgaSysLoggerHotKeyPatch[] = {
 	PATCH_END
 };
 
+// On the inventory screen, clicking an item on the buckazoids when there are
+//  less than three crashes the game. RInvItem:show picks a message by loading
+//  the text resource with the same number as the target item's view property.
+//  The problem is that the buckazoid view is dynamic and changes when the count
+//  gets low. This causes RInvItem:show to attempt to load a text resource that
+//  doesn't exist.
+//
+// We fix this by restoring buckazoid:view after drawing it in inventory.
+//  Sierra fixed this bug in the Amiga and Mac versions by resetting the
+//  buckazoid view to its original value before handling inventory verbs.
+//
+// Applies to: All versions
+// Responsible method: buckazoid:show
+static const uint16 sq1vgaBuckazoidInventorySignature[] = {
+	SIG_MAGICDWORD,
+	0x89, 0xa5,                     // lsg a5 [ buckazoid-count ]
+	0x35, 0x03,                     // ldi 03
+	0x20,                           // ge? [ buckazoid-count >= 3 ]
+	0x30, SIG_UINT16(0x0006),       // bnt 0006
+	SIG_ADDTOOFFSET(+15),
+	0x59, 0x01,                     // &rest 01 [ unnecessary ]
+	0x57, SIG_ADDTOOFFSET(+1), 0x04,// super RInvItem 04 [ super show: &rest ]
+	SIG_END
+};
+
+static const uint16 sq1vgaBuckazoidInventoryPatch[] = {
+	0x67, 0x08,                     // pTos view [ store view ]
+	0x7a,                           // push2
+	0x81, 0xa5,                     // lag a5 [ buckazoid-count ]
+	0x22,                           // lt? [ 2 < buckazoid-count ]
+	0x31, 0x06,                     // bnt 06
+	PATCH_ADDTOOFFSET(+15),
+	PATCH_GETORIGINALBYTES(25, 3),  // super RInvItem 04 [ super show: ]
+	0x69, 0x08,                     // sTop view [ restore view ]
+	PATCH_END
+};
+
 //          script, description,                                      signature                                   patch
 static const SciScriptPatcherEntry sq1vgaSignatures[] = {
+	{  true,     0, "buckazoid inventory",                         1, sq1vgaBuckazoidInventorySignature,          sq1vgaBuckazoidInventoryPatch },
 	{  true,     0, "remove alt+n syslogger hotkey",               1, sq1vgaSysLoggerHotKeySignature,             sq1vgaSysLoggerHotKeyPatch },
 	{  true,    28, "orat sounds",                                 1, sq1vgaSignatureOratSounds,                  sq1vgaPatchOratSounds },
 	{  true,    40, "taste pink ship",                             1, sq1vgaSignatureTastePinkShip,               sq1vgaPatchTastePinkShip },